With a marked worldwide increase in awareness of healthcare issues, the market for home healthcare equipment has grown rapidly. Demand for smaller, more reliable & low-cost battery operated equipment is increasing, so how does the designer aim to meet with these challenges? NEC proposes an answer with their 78K0R/Lx3 series.

Utilising NEC's 16-bit 78K0R CPU core the new All Flash™ MCUs are equipped with the necessary functions to drive systems incorporating LCD segmentated displays while offering a high performance analogue front-end of 12-bit A/D, D/A converters & operational amplifiers - crucial for any equipment operating in the healthcare diagnostics sector.

With the new device family, NEC has also concentrated on reducing standby power consumption of the devices, which now boast a 90% reduction in standby operating current down to 1.2 microamperes (µA) with the LCD enabled, over the company's previous products.

NEC Electronics has achieved this impressive reduction in standby operating current, by employing a capacitor split technique in the silicon design, instead of the conventional LCD Resistive Bias network to drive the LCD. By capacitive splitting the VDD LCD voltage drive, the method produces LCD bias voltages without a wasted DC bias current (a product of Resistive Bias) thereby dramatically cutting the LCD drive current losses.

12 devices fulfil the initial 78K0R/Lx3 series line-up & they available are in a number of different configurations with Flash memory sizes ranging from 64K to 128K, RAM sizes ranging from 4K to 7K & I/O ports ranging from 51 to 83. With a supply of 2.7 to 5.5V the main system clock can run from 2 to 20MHz, with a minimum instruction time of 0.05µs. Supplying 1.8 to 2.7V sees the system clock run from 2 to 5 MHz, with the min., instruction time increasing to 0.2µs.

All of the devices feature a 12 channel 16-bit timer, a Watchdog timer (WDT), a Real-time counter (RTC) in addition to serial interfaces (CSI/UART/simplified I2C - with the LG3 & LGH devices featuring Multimaster I2C), DMA controllers, Low voltage detection (LVI) & Power on clear (POC).

As you would expect the 78K0R/Lx3 series is fully supported by NEC's range of development tools in addition to the MINICUBE on-chip debugging system.

By incorporating into the micro features that would have otherwise required additional external circuitry or dedicated IC devices in addition to reducing standby power consumption, NEC has designed a MCU that not only promises to reduce the overall electronic form factor of designs, but importantly has the potential to reduce component count & therefore cost all while offering extending battery life facilities - three crucial factors that any healthcare equipment developer can ill afford to ignore.

Useful links
NEC Electronics Europe [eu.necel.com]